Spray nozzle assemblies are known which utilize pressurized air for breaking down liquid into relatively small particle sizes. Such nozzle assemblies have particular utility in gas scrubbing applications, where ammonia or urea is sprayed into a discharging stream of combustion gases for removing nitric oxide or other combustion by-products. A problem with such prior spraying nozzles is that relatively high pressurized air is required to achieve adequate liquid particle break-down and atomization, which increases capital and operating costs.